Re: [PATCH v3] mm/page_alloc: clear page->private in free_pages_prepare()

[David Hildenbrand (Arm)]

On 2/9/26 17:05, Zi Yan wrote:
> On 9 Feb 2026, at 11:03, David Hildenbrand (Arm) wrote:
>
> > On 2/9/26 17:00, Zi Yan wrote:
> > > Currently, _mm_id (_mm_ids) overlaps with page->private. At split time,
> > > it should be MM_ID_DUMMY (0), so page->private should be 0 all time.
> >
> > Yes, it's designed like that; because that check here caught it during development :)
> >
> > > It is still better to have the check and fix in place. Why do we want to
> > > skip device private folio?
> >
> > I don't understand the question, can you elaborate?
>
> You said,
> “BTW, I wonder whether we should bring that check back for non-device folios.”
>
> I thought you know why device folio needs to keep ->private not cleared during
> split.

Oh, I thought there was some overlay of ->private with zone-device 
special stuff. But I checked the structs and didn't spot it immediately. 
So I ended up asking Balbir as reply to his latest series that got merged.

--
Cheers,

David